It is a common purpose of linear, reciprocating bearings to be made as free of friction as possible and having lubrication and contamination from foreign matter provided for.
The prior art seems to solve the anti-friction requirements either by: (1) Rollers; (2) Balls which recirculate; (3) Smooth, low coefficient material forming sleeves, such as, Teflon, Nylon and the like; (4) Smooth, but lubricated material of very old tradition such as bronze, brass or babbit, etc. Such prior art relies upon lubrication by equally old and traditional methods, too numerous to list. As for contamination, reliance is placed upon wipers, in themselves a source of friction. As will be seen, this invention seems relatively free and immune from most of these problems.